Sofa



FIG. 1 is a back view of my new sofa design;

FIG. 2 is a side view of the sofa;

FIG. 3 is a front view of the sofa;

FIG. 4 is a perspective view of the sofa;

FIG. 5 is a top view of the sofa; and,

FIG. 6 is a side view of the sofa. 

I claim the ornamental design for a sofa, as shown and described. 